In an image recording device that conducts a recording process (printing process) by ejecting ink, poor ejection, in which the inherently-expected amount of ink is not ejected or ink is not ejected to target spots, or ejection failure, in which ink is not ejected at all, can sometimes occur in the recording process.
Poor ejection or ejection failure can be caused by a foreign body such as paper powder etc. generated from media such as print sheets or the like attached to the ink ejection outlet or to the periphery of the ink ejection outlet. Poor ejection or ejection failure can also be caused in a situation where a minute droplet scattering during ejection is attached to the ink ejection outlet, breaking the surface tension shape (meniscus shape) of the ink, making a bubble block the ink ejection outlet or causing other influence. Further, also in a case when ink has not been ejected for a long period of time, the increased viscosity of the ink can cause poor ejection or ejection failure.
As a method of recovering from poor ejection or ejection failure and preventing them from occurring, for example, a method in which a foreign body or a bubble is discharged together with ink by causing suction from the ink ejection outlet or pressure from the ink supplying side, a method in which a flexible member is pressed on the ejection surface so as to wipe a foreign body or a bubble, and other methods are known. An image recording device uses these methods in order to conduct maintenance for maintaining and restoring the ink ejection function.
Although maintenance is also conducted when receiving instructions from users, image recording devices are also configured to conduct maintenance automatically when the number of printed sheets has exceeded a prescribed value or a period of time that has elapsed has exceeded a prescribed value since the previous maintenance. Hereinafter, maintenance that is conducted automatically is referred to as automatic maintenance.
Regarding automatic maintenance, Patent Document 1 for example discloses an image recording device that conducts automatic maintenance when a recording process in a unit that leads to good user workability has been terminated.    [Patent Document 1] Japanese Laid-open Patent Publication No. 2008-68438